Technical Field
The present disclosure relates to a camera module.
Background Art
Generally, an optical device includes a lens transfer device moving a lens to an optical direction, where the lens transfer device uses an actuator such as an electromagnetic motor or a piezoelectric actuator as a means for generating a power. A cam or a screw is used as a means for transmitting power generated by the actuator.
Thus, the lens transfer device uses the power generated by the actuator to adjust a focus by moving the lens to an optical direction, whereby auto-focusing function is realized.
Meanwhile, a VCM (Voice Coil Motor) is a motor developed based on the principle that a diaphragm in a speaker is vibrated by a force generated between voice current flowing in the coil of a speaker and a magnetic force of a permanent magnet according to the Fleming's left-hand rule. The VCM performs a linear reciprocating motion on a lens at a short distance. The VCM may be used for precise tracking or focusing due to capacity of linearly reciprocating on a short distance compared with a rotation movement by a DC (Direct Current) motor or a stepping motor.
Recently, mobile terminals and PDAs (personal digital assistants) are largely and frequently mounted with a camera module. The camera module may be equipped with an AF (Auto Focusing) function, and a VCM is used for realizing the auto focusing function, where the VCM performs the auto focusing function by vertically moving a lens within a predetermined size of space. In order to perform the AF function in the conventional camera module, a lens position is changed to focus on a particular object.
That is, the camera module includes a VCM actuator for auto focusing, where the VCM actuator must generate an electromagnetic force on a coil for generating a force to drive a lens. To this end, the VCM actuator must be electrically connected to an outside terminal, where the electrical connection is performed by soldering at a contact point. However, there is a disadvantage in soldering due to fluxes or foreign objects falling into a camera module to contaminate an inside of the camera module.
Furthermore, an actuator and a lens barrel are embedded inside a case to be attached to a holder using an epoxy, where, when the case is attached to the holder, the epoxy is disadvantageously compressed to cause the epoxy to be squeezed out of the case and the holder, resulting in the camera module being defective.